1. Field of the Invention
This invention relates to systems for testing the performance of engines and in particular, the performance of engines of the internal combustion type.
2. Prior Art
Previously, in checking the performance of engines, whether newly manufactured or re-manufactured, available test equipment of the water-pump type could not be adjusted to operate the engine at any desired horsepower level since the operating data supplied with the apparatus included an operating chart which was not very accurate unless a certain minimal engine speed was attained. This was due, in part, to the fact that these prior art systems included a water pump which, like a sump pump did not have constant displacement. The use of water pumps also gave rise to maintenance problems due to the fact that water is corrosive and would get past the seals when it started to wear and mix with the lubrication oil in the bearings.
Other types of prior art apparatus used for the same purpose involved the use of electrical generators hooked up to the engine output shaft. However, this type generated high voltage which had to be dissipated somehow, was a fire hazard, was costly and required an electrician in attendance.
The present invention is designed to overcome these problems by employing an oil pump which has constant displacement and therefore can work more effectively at lower engine speeds. The use of an oil pump also obviates many maintenance problems since it is self-lubricating and there are no problems due to faulty seals as there are with pumps designed for use with water. There is also very little fire hazard and maintenance is comparatively negligible.